Muscle Relaxants & Ethanol- Dr. Masserano Flashcards
Examples of acute muscle spasm
-Lower back pain
-Neck pain
-Tension headache
-TMJ
(Treat with Antispasmodic drugs)
Examples of chronic conditions
-Cerebral palsy
-Multiple sclerosis
-Spinal cord injury
-Stroke
-Fibromyalgia
-Myofascial pain syndrom
(Treat with antispasticity drugs)
When to use antispasmodic agents
-Musculoskeletal conditions
When to use antispasticity agents
-Upper motor neuron disorders
List some antispasmodic agents
- Cyclobenzaprine
- Methocarbamol
- Carisoprodol
- Chlorzoxazone
List some anti spastic agents
- Baclofen (safe in elderly)
- Dantrolene
Which two agents have both antispastic and antispasmodic properties
- Diazepam
- Tizanidine (safe in elderly)
What are 1st, 2nd, and 3rd line treatment options for both acute and chronic lower back pain
Acute pain -1st line: Tylenol/NSAIDs -2nd line: Skeletal muscle relaxants -3rd line: Opioids Chronic pain -1st line: Tylenol/ NSAIDs -2nd line: TCAs/SNRIs -3rd line: Skeletal muscle relaxants/ opioids
Diazepam (Valium) MoA
- Potentiates GABA hyperpolarization (Cl- channel) by action on the GABAa receptor
- Site of action: CNS and Spinal cord
- Treats antispasticity and antispasmodic disorders
- Sedation: Main side effect
Baclofen (Lioresal)
- Derivative of GABAb
- Decreases calcium influx and transmitter release (decreasing glutamate)
- Increases K+ efflux (Hyperpolarizing)
- Recommended for treatment of spasticity
- Do NOT abruptly DC, gradually reduce the dose
Tizanidine (Zanaflex)
- Alpha 2 agonist
- Decreases calcium flow into presynaptic neuron
- Decreasing glutamate release
Dantrolene (Dantrium)
- Inhibits RyR1 channel in skeletal muscle
- Inhibits calcium release intracellularly
- Thus inhibiting contractions
- Treatment for spasticity
- Also can treat malignant hyperthermia
- No effect on cardiac/smooth muscle (RyR2 is found here)
Black box warning with Dantrolene (Dantrium)
- Discontinue if no benefit with in 45 days
- Potential for hepatotoxicity
What do alpha 2 agonists do
- Decrease Ca++ uptake
- Decreasing glutamate release
Cyclobenzaprine (Flexril, Amrox) MoA
- Works on upper CNS
- Alpha 2 agonist
- 5HT2 antagonist
- May prolong QT interval
- Potential for serotonin syndrome (when combined with TCAs, SSRIs, SNRIs, MAOIs)
Carisoprodol (Soma) MoA and drug schedule
- Schedule IV
- Do not combine with other CNS depressants
- Potential for drug abuse, dependence, and withdrawal